chromium/third_party/blink/web_tests/fast/forms/month/month-picker-this-month-button.html

<!DOCTYPE html>
<meta name=fuzzy content="maxDifference=0-3; totalPixels=0-1000">
<script src="../../../resources/testharness.js"></script>
<script src="../../../resources/testharnessreport.js"></script>
<script src="../../../resources/testdriver.js"></script>
<script src="../../../resources/testdriver-vendor.js"></script>
<script src="../resources/common.js"></script>
<script src="../resources/picker-common.js"></script>
<script src="../calendar-picker/resources/calendar-picker-common.js"></script>

<input type="month" id="month0" value="2019-02">
<input type="month" id="month1" value="2019-02">
<input type="month" id="month2" value="2019-02" max="2019-05">
<script>

promise_test(() => {
  let monthElement = document.getElementById('month0');
  return openPicker(monthElement)
  .then(() => {
    clickThisMonthButton();

    let splitDate = monthElement.value.split('-');
    let actualTodayDateString = new Date(splitDate[0], splitDate[1] - 1).toDateString();
    let today = new Date();
    today.setDate(1);
    let expectedTodayDateString = today.toDateString();

     assert_equals(actualTodayDateString, expectedTodayDateString, "'This month' button should have updated in-page control to this month");
     assert_equals(internals.pagePopupWindow, null, "Click on 'This month' button should close popup.");
  });
}, "Date picker: 'This month' button should select current month when clicked");

promise_test(() => {
  let monthElement = document.getElementById('month1');
  return openPicker(monthElement)
  .then(() => {
    eventSender.keyDown('Tab'); // Tab over to the 'Clear' button
    eventSender.keyDown('Tab'); // Tab over to the 'This month' button
    eventSender.keyDown('Enter');

    let splitDate = monthElement.value.split('-');
    let actualTodayDateString = new Date(splitDate[0], splitDate[1] - 1).toDateString();
    let today = new Date();
    today.setDate(1);
    let expectedTodayDateString = today.toDateString();

     assert_equals(actualTodayDateString, expectedTodayDateString, "'This month' button should have updated in-page control to this month");
     assert_equals(internals.pagePopupWindow, null, "Click on 'This month' button should close popup.");
  });
}, "Date picker: 'This month' button should select current month when activated with Enter key");

promise_test(() => {
  let monthElement = document.getElementById('month2');
  return openPicker(monthElement)
  .then(() => {
    clickThisMonthButton();

     assert_equals(monthElement.value, "2019-02", "Click on disabled 'This month' button shouldn't change date.");
     assert_not_equals(internals.pagePopupWindow, null, "Click on disabled 'This month' button shouldn't close popup.");

     eventSender.keyDown('Enter');
     assert_not_equals(internals.pagePopupWindow, null, "Enter key should close popup.");
  });
}, "Date picker: 'This month' button should be disabled when current month is not valid");

</script>